howling sound from primary

[sbkchick]

Im getting a howling sound from (I think the primary) when in 1st, 2nd or 3rd gear and let off the throttle! I don't know what it is. I have tightened and loosened the primary bolt and the sound is still there!! ANY IDEA?[confused]

[Theycallmecrash]

High pitched, grinding, consistent with RPM hear it with free revving or only under load/engine braking?

Could be a number of things, the blast is kinda stupid in its design regarding adjusting the primary chain. But if no change with adjusting the chain occurs, then the cause is likely a major repair, related to transmission, and that involves tear down and inspect.